scholarly journals The Chloride Regulation of the Brackish and Fresh-Water Races of Mesidotea Entomon (L.)

1957 ◽  
Vol 34 (2) ◽  
pp. 253-258 ◽  
Author(s):  
A. P. M. LOCKWOOD ◽  
P. C. CROGHAN
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Sea Water ◽  
Chloride Concentration ◽  
Ice Age ◽  
General Level ◽  
Last Ice Age ◽  
The Baltic ◽  
Chloride Regulation

1. Mesidotea entomon (L.) is found in the Baltic and in certain fresh-water lakes in Sweden. It is believed that colonization of fresh water in this region has taken place since the last Ice-age. 2. In the present work animals from brackish and fresh-water habitats have been compared both in respect of the concentration of chloride in their haemolymph and of their ability to survive in media of various salinities. 3. Both fresh-water and Baltic animals have been found able to survive in Plymouth sea water, the concentration of chloride in their haemolymph being close to the concentration of chloride in this medium. 4. Baltic animals could not be acclimatized to fresh water. 5. Animals from both habitats have the same general level of chloride concentration in their haemolymph when acclimatized to dilute sea water. 6. These results are discussed in relation to the evolution of a fresh-water race from a brackish-water race.

Ionic Regulation of the Baltic and Fresh-Water Races of the Isopod Mesidotea (Saduria) Entomon (L.)

1968 ◽  
Vol 48 (1) ◽  
pp. 141-158 ◽  
Author(s):  
P. C. CROGHAN ◽  
A. P. M. LOCKWOOD
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Sodium Concentration ◽  
Relative Volume ◽  
Ice Age ◽  
Ionic Regulation ◽  
Sodium Influx ◽  
Active Uptake ◽  
Concentrated Solution ◽  
The Baltic

1. The isopod Mesidotea entomon has colonized the Baltic and certain Swedish lakes since the end of the last Ice Age. 2. The ionic regulation of Baltic animals and fresh-water animals (L. Mälaren) has been compared. 3. It has been possible to adapt Baltic animals to very dilute media, but 5% Askö sea water (5.5 mM/l. Na) appears to be the limit of adaptation. The haemolymph sodium concentration of Baltic animals from the very dilute media was considerably lowered. 4. The haemolymph sodium concentration in Mälaren animals is high (250 mM/l. Na) and comparable with that in Baltic animals in much more concentrated solution. The haemolymph ionic ratios of the Baltic and freshwater animals are similar. The Cl:Na ratio rises slightly in the more concentrated haemolymph samples. 5. From the concentration of ions in the haemolymph and in the total body water, the relative volume of the haemolymph was calculated. Mälaren animals appear to have a much larger haemolymph volume. 6. The permeability of the animals was determined from the rate of loss of sodium into de-ionized water. The permeability of the Mälaren animals is considerably reduced compared to the Baltic animals. Permeability is not related to the medium to which the animals had been adapted. 7. The sodium influx was determined using 22Na. The rate of active uptake was calculated from this. The maximal rate of active uptake was similar in Baltic and Mälaren animals. The sodium concentration of the medium at which active uptake was half maximum (KM) was considerably lower in Malaren animals than in Baltic animals. 8. The evolution of Mesidotea as a fresh-water animal is interpreted as a result of a reduction in permeability of the external surfaces to NaCl and an increase in the affinity of the active transport mechanism enabling the animal to maintain the haemolymph NaCl concentration in a steady state in fresh water.

scholarly journals Density and Absolute Salinity of the Baltic Sea 2006–2009

2009 ◽  
Vol 6 (2) ◽  
pp. 1757-1817 ◽  
Author(s):  
R. Feistel ◽  
S. Weinreben ◽  
H. Wolf ◽  
S. Seitz ◽  
P. Spitzer ◽  
...  
Keyword(s):  
Equation Of State ◽  
Baltic Sea ◽  
Fresh Water ◽  
Decadal Variability ◽  
Sea Water ◽  
Large Area ◽  
The Baltic Sea ◽  
Sulphate Content ◽  
Density Anomaly ◽  
The Baltic

Abstract. The brackish water of the Baltic Sea is a mixture of ocean water from the Atlantic/North Sea with fresh water from various rivers draining a large area of lowlands and mountain ranges. The evaporation-precipitation balance results in an additional but minor excess of fresh water. The rivers carry different loads of salts washed out of the ground, in particular calcium carbonate, which cause a composition anomaly of the salt dissolved in the Baltic Sea in comparison to Standard Seawater. Directly measured seawater density shows a related anomaly when compared to the density computed from the equation of state as a function of Practical Salinity, temperature and pressure. Samples collected from different regions of the Baltic Sea during 2006–2009 were analysed for their density anomaly. The results obtained for the river load deviate significantly from similar measurements carried out forty years ago; the reasons for this decadal variability are not yet fully understood. An empirical formula is derived which estimates Absolute from Practical Salinity of Baltic Sea water, to be used in conjunction with the new Thermodynamic Equation of Seawater 2010 (TEOS-10), endorsed by IOC/UNESCO in June 2009 as the substitute for the 1980 International Equation of State, EOS-80. Our routine measurements of the samples were accompanied by studies of additional selected properties which are reported here: conductivity, density, chloride, bromide and sulphate content, total CO2 and alkalinity.

scholarly journals Density and Absolute Salinity of the Baltic Sea 2006–2009

Ocean Science ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 3-24 ◽  
Author(s):  
R. Feistel ◽  
S. Weinreben ◽  
H. Wolf ◽  
S. Seitz ◽  
P. Spitzer ◽  
...  
Keyword(s):  
Equation Of State ◽  
Baltic Sea ◽  
Fresh Water ◽  
Decadal Variability ◽  
Sea Water ◽  
Large Area ◽  
The Baltic Sea ◽  
Sulphate Content ◽  
Density Anomaly ◽  
The Baltic

Abstract. The brackish water of the Baltic Sea is a mixture of ocean water from the Atlantic/North Sea with fresh water from various rivers draining a large area of lowlands and mountain ranges. The evaporation-precipitation balance results in an additional but minor excess of fresh water. The rivers carry different loads of salts washed out of the ground, in particular calcium carbonate, which cause a composition anomaly of the salt dissolved in the Baltic Sea in comparison to Standard Seawater. Directly measured seawater density shows a related anomaly when compared to the density computed from the equation of state as a function of Practical Salinity, temperature and pressure. Samples collected from different regions of the Baltic Sea during 2006–2009 were analysed for their density anomaly. The results obtained for the river load deviate significantly from similar measurements carried out forty years ago; the reasons for this decadal variability are not yet fully understood. An empirical formula is derived which estimates Absolute from Practical Salinity of Baltic Sea water, to be used in conjunction with the new Thermodynamic Equation of Seawater 2010 (TEOS-10), endorsed by IOC/UNESCO in June 2009 as the substitute for the 1980 International Equation of State, EOS-80. Our routine measurements of the samples were accompanied by studies of additional selected properties which are reported here: conductivity, density, chloride, bromide and sulphate content, total CO2 and alkalinity.

IV.—The Recent Geological History of the Baltic. Part III: The Western Part of the Sea, the Sound, and the Belts

1905 ◽  
Vol 2 (9) ◽  
pp. 407-413
Author(s):  
H. H. Howorth
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Present Condition ◽  
Geological History ◽  
Land Bridge ◽  
Water Lake ◽  
History Of ◽  
The Baltic ◽  
Fresh Water Lake ◽  
Eastern Baltic

In two previous papers I have set out the conclusions generally held by Northern geologists in regard to the more recent history of the Eastern Baltic, according to which it was once a great enclosed fresh-water lake or sea, the Ancylus lake, which by the breach in the land-bridge connecting Skäne and Denmark was converted into a brackish-water sea, the Litorina sea, which has in turn become less and less saline until it has reached its present condition.

scholarly journals Biodegradation of poly(ε-caprolactone) in natural water environments

2017 ◽  
Vol 19 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Aleksandra Heimowska ◽  
Magda Morawska ◽  
Anita Bocho-Janiszewska
Keyword(s):  
Weight Loss ◽  
Surface Morphology ◽  
Baltic Sea ◽  
Fresh Water ◽  
Sea Water ◽  
Characteristic Parameters ◽  
The Baltic Sea ◽  
Loss Of Weight ◽  
Water Pond ◽  
The Baltic

AbstractThe environmental degradation of poly(ε-caprolactone)[PCL] in natural fresh water (pond) and in The Baltic Sea is presented in this paper. The characteristic parameters of both environments were measured during experiment and their influence on the biodegradation of the samples was discussed. The loss of weight and changes of surface morphology of polymer samples were tested during the period of incubation. The poly(ε-caprolactone) was more biodegradable in natural sea water than in pond. PCL samples were completely assimilated over the period of six weeks incubation in The Baltic Sea water, but after forty two weeks incubation in natural fresh water the polymer weight loss was about 39%. The results have confirmed that the investigated polymers are susceptible to an enzymatic attack of microorganisms, but their activity depends on environments.

Lack of glomerular intermittency in the river lamprey lampetra fluviatilis acclimated to sea water and following acute transfer to iso-osmotic brackish water

1999 ◽  
Vol 202 (8) ◽  
pp. 939-946 ◽  
Author(s):  
J.A. Brown ◽  
J.C. Rankin
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Urine Output ◽  
Neural Control ◽  
Sea Water ◽  
Osmotic Gradient ◽  
Vascular Perfusion ◽  
Lampetra Fluviatilis ◽  
River Lamprey ◽  
Firm Evidence

Previous studies have suggested that in the lamprey Lampetra fluviatilis, in contrast to teleost fish, all glomeruli are actively filtering. In the present study, we have applied the ferrocyanide technique to obtain more definitive values for the population of filtering nephrons in the lamprey under conditions of high (in fresh water) and low (in sea water) glomerular filtration rate (GFR) and when the branchial osmotic gradient was eliminated by acute transfer of freshwater lampreys to iso-osmotic brackish water. These studies demonstrated that the renal antidiuresis in lampreys acclimated to full-strength sea water does not involve any reduction in the filtering population of glomeruli. Transfer to brackish water significantly reduced GFR and thereby urine flow rate (287+/−23 ml kg-1 24 h-1 in fresh water; 6.9+/−2.5 ml kg-1 24 h-1 in brackish water). In four of the eight fish examined, 100 % of glomeruli remained filtering; in the other four fish, non-filtering glomeruli occurred in patches along the kidney, always associated with an absence of vascular perfusion, which implies possible endocrine/neural control of vascular tone. The numbers of non-filtering glomeruli were always small, and these glomeruli do not appear to make a major contribution to the overall decline in urine output. The results provide firm evidence that although lampreys, like teleosts, show considerable variations in urine output, the renal mechanisms by which lampreys and the teleosts achieve this differ fundamentally, with glomerular intermittency playing little or no part in the lamprey.

Plasma Chloride and Sodium, and Chloride Space in the European Eel, Anguilla Anguilla L

1972 ◽  
Vol 57 (1) ◽  
pp. 113-131
Author(s):  
R. KIRSCH
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Chloride Concentration ◽  
Anguilla Anguilla ◽  
The Body ◽  
European Eel ◽  
Plasma Chloride ◽  
Sea Water Adaptation ◽  
Sodium Regulation ◽  
High Degree

1. New intra-vascular cannulation techniques are described, and also an extra-corporal blood circuit containing an artificial heart and a counting cell. This makes possible a continuous study of the radioactivity of the blood. 2. Plasma chloride concentration varies greatly in fresh-water eels despite good sodium regulation. 3. The fresh-water to sea-water adaptation of eels is frequently accompanied by a temporary hypermineralization of the internal medium. This necessitates a high degree of cellular euryhalinity. 4. The sea-water-adapted eel maintains strict homeostasis of its plasma chloride and sodium. 5. The chloride distribution space decreases by 10% when eels are transferred from fresh water to sea water. The internal distribution of chloride is also modified and its fluxes between the ion compartments of the body are considerably increased.

The Urine of Gammarus Duebeni and G. Pulex

1961 ◽  
Vol 38 (3) ◽  
pp. 647-658
Author(s):  
A. P. M. LOCKWOOD
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Blood Concentration ◽  
Sea Water ◽  
The Body ◽  
Absolute Level ◽  
The Absolute ◽  
Urine Formation ◽  
Concentration Of Urine

1. A study has been made of the relation between blood, urine and medium concentrations in the two amphipod Crustacea G. duebeni and G. pulex. 2. G. duebeni produces urine hypotonic to the blood but hypertonic to the medium when it is in media more dilute than 50% sea water. 3. G. pulex forms urine which is hypotonic both to blood and medium when in 2-20% sea water. 4. G. duebeni begins to form hypotonic urine within 2 hr. of transference from 110 to 160% sea water to fresh water. Hypotonic urine formation begins in these circumstances when the blood concentration is up to twice that at which hypotonic urine is formed by animals fully adapted to their medium. 5. It is concluded (a) that the concentration of urine produced by G. duebeni is not dictated solely by the absolute level of the blood concentration; (b) that the formation of urine hypotonic to the blood in a brackish-water animal functions primarily as a means of conserving ions in the body; (c) that the ability to regulate the concentration of the urine with rapidity will be important in an animal living in environments of fluctuating salinities.

scholarly journals Studies on Adaptation to Salinity in Gammarus Spp

1940 ◽  
Vol 17 (2) ◽  
pp. 153-163
Author(s):  
L. C. BEADLE ◽  
J. B. CRAGG
Keyword(s):  
Osmotic Pressure ◽  
Fresh Water ◽  
Brackish Water ◽  
Blood Concentration ◽  
Sea Water ◽  
Marine Species ◽  
Eriocheir Sinensis ◽  
Tolerance Range ◽  
High Concentration ◽  
Ion Absorption

1. Four species of Gammarus were studied: the fresh-water G. pulex, the brackish water G. duebeni, and two normally marine species G. locusta and obtusatus, the former of which has also been recorded from brackish water. 2. The relation between osmotic pressure and chloride of the blood and of the external medium, after sudden transfer to salinities which could be withstood for at least 24 hr., is shown in Fig. 1. 3. The changes in blood osmotic pressure are due to salt and not to water movements. 4. The marine species G. obtusatus and locusta maintain a very hypertonic blood in dilute sea water and can withstand 50% (270 mM.) and 25% (135 mM.) sea water respectively. 5. The brackish water G. duebeni has a tolerance range from pure sea water to water containing a trace of salt, but is not as well adapted to fresh water as G. pulex. 6. For a wide salinity tolerance range two mechanisms are necessary, (a) for regulating the blood concentration within certain limits, and (b) for maintaining a low intracellular concentration of certain ions (e.g. C1) in spite of changes in blood concentration. Defection of the latter mechanism can alone account for the inability of G. pulex to withstand direct transfer to more than about 40% sea water (115 mM.). 7. On the basis of this work and that of others on other animals the following hypothesis is suggested. Adaptation to fresh water has proceeded by two main stages: (a) Probably by active ion absorption, a high blood concentration is maintained (as in Eriocheir sinensis and Telphusa fluviatile) and is associated with a large blood/tissue C1 gradient. Such animals can still be transferred suddenly to a high concentration of sea water. (b) Evolution of the renal salt-reabsorption mechanism, and lowering of both blood concentration and blood/tissue C1 gradient to levels more easily maintained (as in G. pulex and most fresh-water animals). The consequent loss of power to maintain a large blood/tissue C1 gradient entails inability to withstand transfer to more than low concentrations of sea water, unless, as in certain species, a special mechanism is evolved for preventing the blood concentration from rising.

The neoformation of clay minerals in brackish and marine environments

Clay Minerals ◽  
1971 ◽  
Vol 9 (2) ◽  
pp. 209-217 ◽  
Author(s):  
C. V. Jeans
Keyword(s):  
Clay Minerals ◽  
Fresh Water ◽  
Mississippi River ◽  
Brackish Water ◽  
Sea Water ◽  
Water Environment ◽  
Considerable Proportion ◽  
Fine Grained ◽  
Physico Chemical ◽  
Brackish Water Environment

AbstractIt is suggested (1) that large amounts of Al, Fe and Si carried in solution by fresh water are chemically precipitated as hydroxide gels in the brackish water environment of estuaries and deltas, and (2) that these gels are subsequently deposited in both the brackish water environment and in the neighbouring seas, where they become parental material for the neoformation of clay minerals, and various other silicate and iron minerals. The types of neoformed minerals will depend upon both the composition of the parental gels and the physico-chemical milieu of their crystallization. Evidence is discussed supporting this hypothesis from the following sources (1) the concentrations of Al, Fe and Si dissolved in fresh water and in sea-water, (2) experimental work on the crystallization of alumino-siliceous gels, and (3) a study of the precipitation of Si from the waters of the Mississippi River delta.Because of the unusual sediment pattern of present times, this source of neoformed clay minerals and other minerals contributes only a small proportion of the sediments of the brackish parts of estuaries, deltas and the adjacent seas, which are dominated by fine-grained continental detritus. In earlier geological eras, when the world's river systems carried only relatively minor amounts of fine-grained continental detritus, this source of neoformed minerals is likely to have contributed a considerable proportion of the fine-grained sediments of these areas of sedimentation. Three possible examples are discussed.

Sign in / Sign up

Export Citation Format

Share Document